EP1872958B1

EP1872958B1 - Thermal printer and printing device

Info

Publication number: EP1872958B1
Application number: EP20070108845
Authority: EP
Inventors: Toshiharu Toshiba Tec Kabushiki Kaisha Sekino; Tsuyoshi Toshiba Tec Kabushiki Kaisha Sanada; Kiyotaka Toshiba Tec Kabushiki Kaisha Nihashi; Takeshi Toshiba Tec Kabushiki Kaisha Hiyoshi; Kousuke Toshiba Tec Kabushiki Kaisha Takahashi
Original assignee: Toshiba TEC Corp; NCR Corp
Current assignee: Toshiba TEC Corp; NCR Voyix Corp
Priority date: 2006-06-29
Filing date: 2007-05-24
Publication date: 2010-03-31
Anticipated expiration: 2027-05-24
Also published as: CN101817264A; US20120274722A1; EP1872958A2; CN101817264B; US20130002787A1; US20120274723A1; EP2080628B1; EP2080628A1; US8696225B2; CN102059860B; EP2080627A1; CN102059860A; EP2080627B1; EP2080626B1; US8870483B2; US8231291B2; DE602007005547D1; CN101811398B; EP1872958A3; US20080003040A1

Description

The present invention relates to a thermal printer mounted on, e.g., a register, and a printing device.
There has been known a thermal printer mounted on, e.g., a register or the like, to print various pieces of information in a receipt made of thermosensitive paper. Normally, for example, as described in Jpn. Pat. Appln. KOKAI Publication No. 11-286147 , the thermal printer includes a thermal head for heating the thermosensitive paper and a platen roller for pressing the thermosensitive paper to the thermal head.
In such a thermal printer, when there is no more thermosensitive paper, a user must open a cover to supply new thermosensitive paper. Accordingly, a recent thermal printer may include a release button for easily opening a cover by a single action.
However, the conventional thermal printer has used a coil spring to return the pressed release button to its original position. Thus, a space must be provided to receive the coil spring in the cover, which has caused enlargement of the thermal printer. An object of the present invention to provide a compact thermal printer which enables easy opening of a cover by a single action.
In the above thermal printer, the thermosensitive paper passes between the thermal head and a platen, and printing is carried out on the thermosensitive paper by heat added to the thermal head. The thermosensitive paper is normally wound into a roll shape, and an opening/closing cap in an upper part of the casing must be opened when the thermosensitive paper is replaced.
The following problem has occured in the above thermal printer. That is, the thermal head is disposed on the casing side, the platen is disposed on the cap side, and the thermal head and the platen normally come into contact with each other when pressed.
Consequently, when the cap is opened/closed, the platen interferes with the casing side. Thus, a complex operation of opening/closing the opening/closing cap after shifting it in a direction away from the thermal head, or the like is necessary.
It is therefore an object of the present invention to provide a thermal printer which can open an opening/closing cap by an easy operation when thermosensitive paper is replaced.
As described in U.S. Patent No. 3,118,469 , there has been known a thermal printer in which a cover is fixed to a printer main body to be rotated and opened/closed, a thermal head is disposed on a printer main body side, and a platen roller is disposed on a cover side. In this case, to obtain a desired conveying force and desired printing pressure, the thermal head is pressed to the platen roller in a closed state. In this thermal printer, the printer main body and the cover are engaged with each other by a locking mechanism to maintain the closed state, and the engagement of the locking member is released to move the cover away from the printer main body, thereby setting an opened state. However, in the thermal printer of this configuration, as the thermal printer is pressed to the platen roller in the closed state to generate a frictional force, even if the engagement of the locking member is released, this frictional force produces resistance, making opening/closing difficult. It is therefore an object of the present invention to provide a thermal printer which enables easy and smooth opening/closing.
There has been known a printing device which includes a first printing part positioned on a sheet conveying-direction downstream side in a sheet conveying path and a second printing part positioned on a sheet conveying-direction upstream side in a device main body, and performs printing on both surfaces of a sheet by the first and second printing parts.
For example, as described in U.S. Patent No. 6,784,906 , the first printing part includes a first thermal head as a printing head, and a first platen roller arranged to face the first thermal head via the sheet conveying path and to convey the sheet. The second printing part includes a second thermal head as a printing head, and a second platen roller arranged to face the second thermal head via the sheet conveying path and to convey the sheet.
An opening/closing member is disposed in the device main body, and sheets are replenished by opening this opening/closing member. The first platen roller of the first printing part and the second thermal head of the second printing part are fixed to the opening/closing member. By closing the opening/closing member, the first thermal head is pressed to the first platen roller, and the second thermal head is pressed to the second platen roller. The first and second thermal heads are pressed by spring forces of first and second spring members.
However, as pressing directions of the first and second thermal heads to the first and second platen rollers are reverse to each other, there has conventionally been a problem that their pressing forces affect each other, and it is difficult to set head loads of the first and second thermal heads on the first and second platen rollers to proper states, making it impossible to expect good printing.
From US-A-6,155,731 a thermal printer is known, comprising a housing in which a space is formed to receive thermosensitive paper, printing means disposed in the housing to print various pieces of information in the thermosensitive paper, a cover which is disposed in the housing and which comes into contact with and separates from the housing when rotated, thereby opening and closing the space, urging means for urging the cover in a direction away from the housing an engaging part which is disposed in the housing and which prevents the movement of the cover in the direction away from the housing when engaged with the cover, a pressed part which is disposed in the cover and which moves the engaging part when pressed, thereby releasing engagement between the cover and the engaging part, a support shaft body disposed in a position away from the pressed part to rotatably support the pressed part , and elastic means arranged on a side opposed to the pressed part by using the support shaft body as a reference to urge the pressed part in a direction away from the engaging part.
A similar printing unit is known from US 2003/118390A1 .
An object of the present invention to provide a printing device which can properly obtain head loads of first and second printing heads on first and second platens.
According to the present invention,
a thermal printer comprises:

a housing in which a space is formed to receive thermosensitive paper;
printing means disposed in the housing to print various pieces of information in the thermosensitive paper;
a cover which is disposed on the housing and which comes into contact with and separates from the housing when rotated , thereby opening and closing the space;
a cover frame which is fixed to an inner surface of the cover and which has an engaging shaft body;
urging means for urging the cover in a direction away from the housing;
an engaging part which is disposed in the housing and which prevents the movement of the cover in a direction away from the housing when engaged with the engaging shaft body,
a release button which is provided for the cover and which comprises a pressed part and a support shaft body,
the pressed part being disposed on the cover moving the engaging part when pressed, thereby releasing engagement between the engaging shaft body and the engaging part,
the support shaft body being disposed in a position away from the pressed part to rotatably support the pressed part; and
elastic means arranged on a side opposed to the pressed part by using the support shaft body as a reference to urge the pressed part in a directon away from the engaging part,

According to this configuration, a cover of the thermal printer can be easily opened by a single action. Additionally, the thermal printer can be made compact.
The invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a thermal printer when a cover is closed according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of the thermal printer when the cover is opened according to the embodiment;
FIG. 3 is a front diagram showing a release button and a hook according to the embodiment;
FIG. 4 is a schematic diagram showing a state when a button main body is not pressed according to the embodiment;
FIG. 5 is a schematic diagram showing a state the instant engagement between the hook and an engaging shaft body is released according to the embodiment;
FIG. 6 is a schematic diagram showing a state when the cover is raised from a housing according to the embodiment.

FIG. 1 is a schematic diagram of a thermal printer when a cover 20 is closed and FIG. 2 is a schematic diagram of the thermal printer when the cover is opened. For example, the thermal printer is mounted on a register or the like to be used for printing a receipt. As shown in FIGS. 1 and 2, such a thermal printer includes a housing 10 as a main body casing, and a cover 20 for opening/closing an opening 10a of the housing 10.
The housing 10 has a rectangular box shape, and a housing frame 11 is arranged therein. The housing frame 11 includes two frame bodies 12 arranged on both sides of the housing 10, and a reception space (space) S is formed nearby to receive thermosensitive paper P. The thermosensitive paper P is wound in a roll to be placed on a base 10b fixed to a bottom wall of the housing 10. There is no particular limitation on types of thermosensitive paper. According to the embodiment, however, a type having thermosensitive layers on both first and second surfaces which are respectively a front and a back is used.
The frame bodies 12 extend from the bottom wall of the housing 10 to positions near the opening 10a of the housing 10, and a connecting shaft 13 is set in a predetermined position in parallel with the bottom wall of the housing 10. Each frame body 12 is formed into a plate shape, and fixed to the bottom wall of the housing 10 by screws or the like.
In the housing 10, a printing device 14 is disposed on a side opposed to the housing frame 11 to print various pieces of information on the thermosensitive paper P by using the reception space S as a reference. The printing device 14 includes a first printing unit 141 in charge of printing on the first surface which is the front of the thermosensitive paper P, and a second printing unit 142 in charge of printing on the second surface which is the back of the thermosensitive paper P.
The first printing unit 141 includes a first thermal head 141a fixed to the housing 10, and a first platen roller 141b fixed to the cover 20. The first thermal head 141a extends in parallel with the connecting shaft 13 to heat the first surface which is the front of the thermosensitive paper P in accordance with information from a controller (not shown). The first platen roller 141b extends in parallel with the connecting shaft 13, i.e., in parallel with the first thermal head 141a, to press the thermosensitive paper P to the first thermal head 141a.
The second printing unit 142 includes a second thermal head 142a fixed to the cover 20, and a second platen roller 142b fixed to the housing 10. The second thermal head 142a extends in parallel with the connecting shaft 13 to heat the second surface which is the back of the thermosensitive paper P in accordance with information from the controller (not shown). The second platen roller 142b extends in parallel with the connecting shaft 13, i.e., in parallel with the second thermal head 142a, to press the thermosensitive paper P to the second thermal head 142a.
Each of the first and second platen rollers 141b, 142b is rotated in a predetermined direction by a driving device 15, and conveys the thermosensitive paper P in an arrow direction a by using friction from a rubber film formed in the first surface which is a roller surface.
The driving device 15 includes a plurality of driving rollers 151 (only two are shown) for driving the first and second platen rollers 141b, 142b, and a stepping motor 152 for driving the driving rollers 151.
When the stepping motor 152 is operated, the plurality of driving rollers 151 are driven, and the first and second platen rollers 141b, 142b are rotated in predetermined directions. The thermosensitive paper P held between the thermal head 141a and the first platen roller 141b and between the second thermal head 142a and the second platen roller 142b is conveyed in the arrow direction a by friction from the first and second platen rollers 141b, 142b. At this time, the first and second thermal heads 141a, 142a heat the thermosensitive paper P to form characters or symbols in the first and second surfaces which are respectively a front and a back.
In the housing 10, a rodlike hook 16 is disposed in a place which is opposed to the connecting shaft 13 and on the right as seen by the user (before paper surface in FIG. 1) by using the reception space S as a reference.
FIG. 3 is a front diagram of the release button 30 and the hook 16.
As shown in FIG. 3, the hook 16 is rotatably supported by a shaft body 17 fixed to the housing 10, and includes a notch 16a formed in a place opposed to the connecting shaft 13 to be engaged with an engaging shaft body 23 (described below) arranged in the cover frame 21.
In the hook 16, spring coils 18 are connected to places opposed to each other around the shaft body 17. These spring coils 18 are connected to the housing 10 to urge the hook 16 in an arrow direction A.
A pressed surface 16b pressed by a pressing surface 31a formed in a button main body 31 (described below) is formed in an upper part of the hook 16, i.e., a place opposed to the cover 20 in a state in which the cover 20 closes the reception space S of the housing 10. The pressed surface 16b is inclined to approach the bottom wall of the housing 10 as it approaches the connecting shaft 13.
As shown in FIGS. 1, 2, the cover 20 includes upper and side walls 20a and 20b, and has a U sectional shape. The cover frame 21 is fixed in an inner surface of the cover 20, i.e., a place facing the housing 10 in a state in which the cover 20 closes the reception space S of the housing 10.
The cover frame 21 includes two frame bodies 22 arranged on both sides of the cover 20. Each frame body 22 is formed into a plate shape, and fixed to the inner surface of the cover 20 by screws or the like.
The frame bodies 22 include first and second engaging plate parts 22a and 22b. The first engaging plate part 22a extends into the housing 10, and the connecting shaft 13 is rotatably connected to its predetermined place. Accordingly, the cover 20 is supported to rotate around the connecting shaft 13 with respect to the housing 10. Springs 13a are disposed in both ends of the connecting shaft 13. These springs 13a urge the cover frame 21 in an arrow direction B of FIG. 2.
The second plate parts 22b extend in a direction away from the cover 20. Among these, in the second engaging plate part 22b of the frame body 22 arranged on the right as seen by the user, an engaging shaft body 23 is disposed to be engaged with the hook 16. The engaging shaft body 23 extends in parallel with the connecting shaft 13 to reach the vicinity of an inner surface of the side wall of the housing 10.
The release button 30 is arranged in a place of the cover 20 which is the right side as seen by the user. As shown in FIG. 3, the release button 30 includes a button main body (pressed part) 31, an arm 32, a support shaft body 33, and a leaf spring 34. These are formed by integral molding, and the button main body 31, the support shaft body 33 and the leaf spring 34 among them are linearly arrayed.
As shown in FIGS. 1, 2, the button main body 31 is arranged in the notch 20c formed in the cover 20. In its lower part, i.e., a place facing the housing 10 in the state in which the cover 20 closes the reception space S of the housing 10, as shown in FIG. 3, a pressing surface 31a for pressing the pressed surface 16b of the hook 16 is formed. As in the case of the pressed surface 16b, the pressing surface 31a is inclined to approach the bottom surface of the housing 10 as it approaches the connecting shaft 13.
As shown in FIG. 3, the arm 32 is arranged in the cover 20 to extend from the side part of the button main body 31 toward the connecting shaft 13. The support shaft body 33 is connected to an end of the arm 32 opposed to the button main body 31, and supported to rotate around an axis parallel to the connecting shaft 13 by support means (not shown) disposed in the cover 20.
The leaf spring 34 extends from a place of the support shaft body 33 opposed to the arm 32 toward the connecting shaft 13. In a place nearest the connecting shaft 13, an abutment part 34a is formed to extend toward an upper wall 20a of the cover 20. The abutment part 34a always elastically abuts the upper wall 20a. Accordingly, the release button 30 is always urged to the upper side by the leaf spring 34.

Opening Operation of Cover 20

FIG. 4 is a schematic diagram showing a state in which the button main body 31 is not pressed according to the embodiment, FIG. 5 is a schematic diagram showing a state the instant engagement between the hook 16 and the engaging shaft body 23 is released according to the embodiment, and FIG. 6 is a schematic diagram showing a state when the cover 20 is raised from the cover 10 according to the embodiment.
When there is no more thermosensitive paper P, the button main body 31 of the release button 30 is pressed downward by a finger f of the user. FIG. 4 shows a state immediately before the button main body 31 is pressed.
When the button main body 31 is pressed, the release button 30 rotates around the support shaft body 33, and the pressing surface 31a formed in the lower part of the button main body 31 abuts the pressed surface 16b formed in the upper part of the hook 16.
When the button main body 31 is pressed more from this state, the hook 16 rotates around the shaft body 17 by pressing from the pressing surface 31a of the button main body 31, and the engaging shaft body 23 formed in the cover frame 21 is removed from the notch 16a of the hook 16. FIG. 5 shows a state the instant the engaging shaft body 23 is removed from the notch 16a of the hook 16.
With disengagement between the hook 16 and the engaging shaft body 23, the cover 20 is urged by the spring 13a arranged in the connecting shaft 13 to rotate around the same, thereby raising the cover 20 slightly. FIG. 6 shows a state when the cover 20 is slightly raised.
At this time, the button main body 31 of the release button 30 is still pressed by the finger f of the user. Accordingly, positions of the release button 30 and the hook 16 are not changed while the cover 20 and the cover frame 21 are raised. Thus, the engaging shaft body 23 disposed in the cover frame 21 is raised together with the cover 20 to move to a position higher than the notch 16a of the hook 16. As a result, even when the pressing of the button main body 31 is released, the engaging shaft body 23 and the hook 16 are not engaged with each other again.
When the pressing of the button main body 31 is released, the release button 30 is urged by the leaf spring 34 to rotate around the support shaft body 33, and the button main body 31 is returned to its original position. After the button main body 31 is returned to the original position, the hook 16 is urged by the spring 13a to rotate around the support shaft body 33, and to be returned to its initial position.
As described above, the cover 20 is easily opened only by pressing the button main body 31 of the release button 30. Furthermore, when the pressing of the release button 30, the release button 30 is returned to its original position by urging from the leaf spring 34.

Effects of Embodiment

According to the embodiment, the leaf spring 34 is used for returning the release button 30 pressed by the user to its original position. Thus, the thermal printer is made compact as no reception space as large as the conventional coil spring is necessary.
According to the embodiment, the button main body 31, the support shaft body 33, the leaf spring 34, and the abutment part 34a constituting the release button 30 are linearly arrayed. Thus, even when a large force is applied to the button main body 31, the release button 30 is not twisted, and accordingly inclination of the button main body 31 is prevented.

Claims

A thermal printer comprising:
a housing (10) in which a space (S) is formed to receive thermosensitive paper (P);

printing means (14) disposed in the housing (10) to print various pieces of information in the thermosensitive paper (P);

a cover (20) which is disposed on the housing (10) and which comes into contact with and separates from the housing (10) when roated, thereby opening and closing the space;

a cover frame (21) which is fixed to an inner surface of the cover (20) and which has an engaging shaft body (23);

urging means (13a) for urging the cover (20) in a direction away from the housing (10);

an engaging part (16) which is disposed in the housing (10) and which prevents the movement of the cover (20) in a direction away from the housing (10) when engaged with the engaging shaft body (23);

a release button (30) which is provided on the cover (20) and which comprises a pressed part (31) and a support shaft body (33),

the pressed part (31) being disposed on the cover (20) moving the engaging part (16) when pressed, thereby releasing engagement between the engaging shaft body (23) and the engaging part (16),

the support shaft body (33) being disposed in a position away from the pressed part (31) to rotatably support the pressed part (31); and

elastic means (34) arranged on a side opposed to the pressed part by using the support shaft body (33) as a reference to urge the pressed part (31) in a direction away from the engaging part (16),
wherein when the engaging shaft body (23) and engaging part (16) are disengaged, the urging means (13a) moves the cover frame (21) in the direction away from the housing (10) so as to move the engaging shaft body (23) to a position away from the engaging part (16), the release button (30) rotates around the support shaft body (33), and the pressed part (31) being pressed by a user's finger is not moved.
The thermal printer according to claim 1, characterized in that the elastic means is a leaf spring (34).
The thermal printer according to claim 1, the pressed part (31), the support shaft body (33) and the elastic means (34) are linearly arrayed.
The thermal printer according to claim 1, characterized in that the pressed part (31), the support shaft body (33), and the elastic means (34) are integral.